Control system for maintaining different temperature ranges within compartments having a common refrigerating unit



Dec. 28, 1965 CONTROL SYSTEM FOR MAINTAINING DIFFERENT TEMPERATURE RANGES WITHIN COMPARTMENTS HAVING A COMMON REFRIGERATING UNIT Filed April 4, 1963 C. FISCHER 2 Sheets-Sheet 1 Fig.

Harry 6. F Ike/1e! INVENTOR.

BY gm,

Dec. 28, 1965 H c FISCHER 3,225,559

CONTROL SYSTEM FOR MAINTAINING DIFFERENT TEMPERATURE RANGES WITHIN COMPARTMENTS HAVING A COMMON REFRIGERATING UNIT Filed April 4, 1963 2 Sheets-Sheet 2 Fig. 3

Com.

Condenser 76 Drier Harry 6. Fischer INVENTOR.

WW 3M United States Patent This invention relates to a combined water cooler and refrigerator apparatus and more particularly to a control system associated therewith whereby a standby supply of Water is maintained in a cool condition at temperatures which necessarily differ from refrigerator compartments also associated with the apparatus for preserving food and forming ice cubes.

The apparatus and associated control system of the present invention deals with the problem of maintaining a standby water supply at the proper temperature for drinking purposes by use of the same refrigerant circuit available for maintaining refrigerator compartments at lower temperature ranges necessary to preserve food and freeze ice cubes. In designing equipment of this type, difliculty has heretofore been encountered when using a single refrigerant circuit inasmuch as the cooling loads within the refrigerator compartments and the frequency with which drinking water was to be withdrawn from the standby water supply varied relative to each other to such a degree as to render operation unsatisfactory after prolonged used. Accordingly, infrequent use of the standby water supply for drinking purposes ultimately resulted in freezing of the drinking water or frequent use of the refrigerator compartment spaces or withdrawal of ice cubes would also produce bad results. Frequent withdrawal of large quantities of drinking water would also resuit in drinking water at unpalatably high temperatures. In order to cope with the foregoing problems, multiple refrigeration units have been utilized in association with complex control systems so as to render combined water coolers and refrigerator units bulky, large and expensive.

It is therefore a primary object of the present invention to provide a control system for a refrigeration unit associated in common with a water cooler and a refrigerator capable of maintaining the refrigerator compartments and standby drinking water supply at the proper respective temperatures despite any wide variation in use as aforementioned.

In accordance with the foregoing object, a refrigeration circuit is utilized which favors the refrigerator compart ments over the standby drinking water tank so that the ice cubes within the refrigerator will be substantially frozen before the standby water supply is cooled to the desired drinking temperatures. However, the refrigeration unit is set into operation exclusively in response to demand from the standby drinking water supply for cooling thereof when its temperature rises above a predetermined value. The demand for freezing from the refrigerator compartments on the other hand, is met by energization of a loading heater by means of which the standby water supply is warmed sufiiciently within its drinking temperature range so that the refrigeration unit will be set into operation by an artificial demand of the standby water supply. Accordingly, operation of the refrigeration unit for sequentially cooling the refrigerator compartments and the standby water supply will be controlled only by the demand of the standby Water supply which demand either arises in an uncontrolled manner due to use or other factors or in a controlled manner by deliberate warming of the standby water supply in response to demand from the freezer compartments.

The foregoing operation is achieved by a relatively simple control system and a loading heater for the standby water supply in cooperation with the control circuit for the refrigeration unit. Effective use of a single refrigerant circuit is thereby made possible to achieve the desired cooling of the drinking water supply and refrigerator compartments without the restrictions or limitations on use heretofore found necessary in order to obtain satisfactory performance.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of a combined water cooler and refrigerator unit made in accordance with the present invention.

FIGURE 2 is a rear elevational view of the unit illustrated in FIGURE 1.

FIGURE 3 is a diagrammatic illustration of the thermal and water distributing circuits associated with the apparatus of the present invention,

FIGURE 4 is an electrical circuit diagram associated with the control system of the present invention.

Referring now to the drawings in detail, it will be observed from FIGURES 1 and 2, that the combined unit generally referred to by reference numeral 19 may be enclosed by an insulated cabinet 12 provided with an insulated door 14 which when opened exposes a cold refrigerator compartment 16 within which food may be stored and preserved. Also mounted within the refrigerator compartment is the usual cold plate 18 within which the evaporator coil portion of the refrigeration circuit is housed and on which ice cube trays 20 may be supported for the purpose of freezing ice cubes therein. Mounted below the cold compartment 16 behind the vented wall panel 22, the other components of the refrigeration circuit may be mounted including for example the refrigerant circulating compressor, the cooling fan, the condenser and the drier described hereafter. A basin 24 is mounted on top of the housing 12 for collecting and draining water that may be dispensed either from a cold water bubbler valve 26 of conventional construction or a hot water valve 28. Accordingly, the back panel 30 of the unit 10 is provided with an opening 32 through which a waste water drain connection may be made to the basin 24. Also provided on the back panel 30, are openings 34, 36 and 38 through which connections may be made for an inlet water supply, a cold water drain and a hot water drain respectively.

Referring now to FIGURE 3 in particular, it will be observed that a water inlet connection 40 is provided for supply of water to a standby water storage container in the form of a cold water tank 42 within which a drinking water supply is contained. The inlet connection 40 is therefore connected to the cold water tank through the conduit 44 to which a T-fitting 46 is connected for also supplying inlet water to the hot water valve assembly 26 from which water is admitted through line 48 to the hot water tank 50. Accordingly, inlet water may be supplied through the valve assembly 28, line 52 and T-coupling 54 to the hot water tank which may also be drained when desired through the hot water drain connection 56. Cold water may also be drained from the cold water tank 42 and the bubbler valve 26 through line 58 and the cold water drain connection 60. The line 58 is therefore connected to the bottom of the cold water tank 42 by the T- coupling 62. Water is therefore also withdrawn from the cold water tank 42 for drinking purposes through the coupling 62 and the bubbler valve 26. Air may be bled from the tank in the usual fashion by means of the capillary tube 64. Hot water tank 50 is provided with a thermostatically controlled heater while the cold water tank is provided with cooling coils 66 by means of which the water is maintained in a cool condition for drinking purposes. However, pursuant to the principles of the present invention, the cold water tank 42 is also provided with a loading heater element 68 which is also thermostatically controlled as will be hereafter explained.

The cooling coils 66 are in series with evaporative coils in the cold plate 18 as shown in FIGURE 3 to form a refrigerant circuit whereby the cold compartment 16 and the freezer compartment 70 defined between the evaporator cold plates 18 are maintained at the proper temperatures. The refrigerant circuit includes an insulated suction line 72 connected to one end of the cooling coil 66 for the cold water tank and to the inlet end of a refrigerant circulating compressor 74 which is driven by an electric motor. The discharge line 76 from the compressor is therefore connected to the condenser coils 78 of an air cooled type of condenser 80 in order to liquefy the refrigerant which is conducted through a dryer 82. The refrigerant emerging from the dryer is conducted through a capillary tube assembly 84 for circulation through the cold plates 18 within which it is evaporated when absorbing heat and then conducted by the line 86 to the inlet end of the cooling coil 66 for the cold water tank. It will therefore be apparent, that when the compressor 74 is operative, the refrigerant cycle will favor the cooling load of compartment 16 so as to substantially freeze any ice cubes that may be within the below freezing compartment '70 before the standby drinking water supply within the cold water tank 42 is cooled to the drinking temperatures above freezing.

Referring now to FIGURE 4, it will be observed that an electrical control circuit is provided for control of the refrigerant circuit. The circuit therefore is connected to a source of electrical energy through the powerlines 88 and 90 across which is connected a heater element 92 for the hot water tank 50, this heater element being controlled by a thermostatic switch 94 connected in series therewith across the powerlines. A thermostatic switch 96 is also associated with the cold water tank so that when the standby drinking water supply is above approximately 47 F. approaching the upper limit of the drinking temperature range, it will be in the position illustrated in FIGURE 4 establishing an electrical connection from the powerline 88 to the line 98 completing an energizing circuit through the usual condenser cooling fan motor 100 connected between the line 98 and the powerline 90. The line 98 is also connected to the heater element of an overload relay 102 in series with its thermal switch. An electrical connection is therefore established through the overload relay 102 between the line 98 and the line 104 which is connected to a pair of motor windings of the compressor motor 106 including the lower resistance main winding 108 and the starting winding 110. The main winding 108 is therefore connected through the conductor 112 to one terminal of the coil 114 of the motor starting relay 116. The other terminal of the coil 114 is connected to the power line 90 so as to complete an energizing circuit through the starting relay. Energization of the relay coil by the high starting current will therefore close the relay switch 118 so as to complete an energizing circuit through the motor winding 110 by means of the line 120. After the compressor is started by the motor 106 so that the large static load thereon has been reduced, a corresponding reduction in the winding current causes deenergiza tion of the relay 116 so that opening of the relay switch 118 removes the starting winding from the circuit. Actuation of the cold water tank thermostatic switch 96 to its other position when the standby water supply is within the drinking temperature range, will be operative to establish an electrical connection between the powerline 88 and the line 98 through the loading heater 68 if the thermostatic switch 122 associated with the freezer compartment 70 is in its illustrated closed position. Accordingly, one terminal of the heater 68 is connected to the thermostatic switch 122 and one contact of the thermostatic switch 96. The freezer thermostatic switch 122 will be in its illustrated closed position when the below freezing temperature within the freezer compartment exceeds the desired upper temperature range limit of substantially 10 degrees F.

With continued reference to FIGURE 4, operation of the refrigeration control system will become apparent. With the water in the ice trays and in the cold water tank above the desired respective temperature ranges, both thermostatic switches 96 and 122 will be in the positions illustrated. Accordingly, the thermostatic switch 96 will establish parallel energizing circuits through the fan motor 100, and the main winding 108 of the motor 106 in series with the relay coil 114 as a heat removal demand of the cold water tank. Energization of the relay 114 will close the relay switch 118 so as to complete an energizing circuit through the motor winding 110 in order to start the compressor 74. Refrigerant will then be expanded through the capillary tube assembly 84 after passage through the condenser cooled by air flow induced by the fan motor and dryer 82 for heat exchange with the cold compartment 16 and the ice cube trays within the freezer compartment 70. After absorption of heat from the freezer compartment to almost freeze the ice cubes therein at below 10 degrees F., refrigerant will then rise in the suction line 86 for heat exchange with the standby drinking water supply within the cold water tank 42 encircled by the cooling coils 66 conducting the refrigerant. At this point, the thermostat switch 122 associated with the freezer compartment will open so as to prevent energization of the loading heater 68 when the thermostatic switch 96 is subsequently actuated to its other position upon cooling of the standby water supply in the cold water tank to drinking temperatures. Accordingly, the heat removal demand of the standby water supply will be satisfied substantially at the above freezing temperature of 39 degrees F. so as to actuate the thermostatic switch 96 to its other position from that illustrated in FIGURE 4. The energizing circuit for the motor 106 is thereby interrupted so as to stop operation of the refrigeration unit. Should the temperature within the freezer compartment rise above the desired upper limit of its associated temperature range, before any demand for cooling is made by the cold water tank, the thermostatic switch 122 will close so as to complete an energizing circuit through the heater 68 which will then be connected by the thermostatic switch 96 to the line 98 placing the heater 68 in series with the motor 106 and relay 116. The standby water supply within the cold water tank will thereby be artificially warmed by the heater 68 to a temperature of substantially 47 degrees F. Inasmuch as the resistance of the heater 68 is relatively large as compared to the main winding 108 of the motor 106, the motor will not become energized until the heater 68 is cut out of the circuit, this occurring when the standby water supply has risen to 47 degrees F. causing its associated thermostatic switch 96 to move to the position illustrated in FIGURE 4. The compressor motor 106 will then be energized not in response to the demand created by closing of the thermostatic switch 122 but rather by the demand created by movement of the thermostatic switch 96 to its illustrated position. Accordingly, there will be a delay between the cooling demand of the freezer compartment 70 and operation of the refrigeration unit by means of which the refrigeration unit will have sufiicient time within which to balance before it is restarted. It will also be appreciated, that demand originating directly with the cold water tank will start the refrigeration unit without resort to the heater 68. The overload relay 102 being inerconnected between the compressor motor 106 and the heater 68 when in circuit, will be operative to disable the refrigeration unit due to overload of either the compressor motor or the heater 68.

From the foregoing description, the construction, operation and utility of the apparatus and control system of the present invention will be apparent. It will therefore be appreciated that the apparatus of the present invention may be effective to effect compartment cooling, ice cube freezing and water cooling from a single refrigeration circuit wherein cold plate temperature for ice cube freezing is achieved without any danger of freezing the standby cold water supply. Operation of the refrigeration unit will exclusively satisfy the cold water temperature requirement with the cold water supply being artificially warmed when the cold refrigerator compartment temperature calls for removal of heat. The delay involved between demand of the refrigerator compartment and the following demand from the standby water supply tank will also provide suflicient time within which the compressor may balance before starting of the refrigeration cycle so as to avoid short cycling. Advantage may also be taken of the foregoing delay in energization of the compressor motor and the loading heater to eliminate the thermostat 122 so that a cooling cycle is obtained periodically with a fixed and uniform delay therebetween, assuming that heat leakage into the refrigerator compartment is constant. Thus, a simplified unit may be utilized, controlled only by thermostat 96 where the heater 68 is so sized that as soon as the compressor has completed one cycle, the heater will be energized to warm the standby drinking water to the temperature at which the thermostat cuts in the compressor motor. The simplified unit would therefore be suitable for modern buildings wherein the temperatures never fall below 55 F. or rise above 100 F. for example. Thus, for most conditions in offices, the simplified unit would operate satisfactorily where a loading heater of proper wattage is chosen, as for example 100 watts.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope if the invention as claimed.

What is claimed as new is as follows:

1. In combination with a combined water cooler and refrigerator having a single refrigerant circuit in heat exchange relation with a freezer compartment and a standby water supply, a control system comprising, water cooling control means responsive exclusively to increase in temperature of water in said standby water supply above a predetermined temperature for rendering said refrigerant circuit operative to substantially lower the temperature in the freezer compartment to a lower limit before cooling the standby water supply, heating means operatively mounted on said standby water supply for deliberate warming of the water therein above said predetermined temperature, and freeze demand means 0peratively connected to said heating means for energization thereof to warm the water only in response to a rise in temperature of the freezer compartment above said lower limit prior to said increase in temperature of the water in the standby water supply above the predetermined temperature.

2. The combination of claim 1 wherein said water cooling control means comprises, thermostatic switch means operative in one position to disconnect the heating means and render the refrigerant circuit operative and in a second position to condition the heating means for energization by the freeze demand means.

3. The combination of claim 2, including overload means operatively connected to the heating means and the water cooling control means to disable operation of both the heating means and the refrigerant circuit in response to overload of either.

4. The combination of claim 1, including overload means operatively connected to the heating means and the water cooling control means to disable operation of both the heating means and the refrigerantcircuit in re sponse to overload of either.

5. In combination with a thermal circuit and a pair of chambers in heat exchange relation with said thermal circuit for maintaining said chambers within different temperature ranges; means for rendering the thermal circuit operative to sequentially reestablish said different temperature ranges in the respective chambers in response to a change in temperature of only one of said chambers to a value outside of the temperature range associated therewith, heating means rendered operative to controllably change the temperature of said one chamber to said value outside of the temperature range associated therewith, means responsive to a change in temperature of the other chamber outside of its associated temperature range for rendering the heating means operative, and means for disabling the heating means when the temperature of said one chamber is within its associated temperature range.

6. The combination of claim 5, wherein the temperature range associated with said one chamber is substantially between 39- F. and 47 F. and the temperature range associated with the other chamber has an upper limit of 10 F.

7. In combination with a combined water cooler and refrigerator having a single refrigerant circuit in heat exchange relation with a freezer compartment and a standby water supply, a control system comprising, water cool ing control means responsive exclusively to increase in temperature of water in said standby water supply above a predetermined temperature for rendering said refrigerant circuit operative to substantially lower the temperature in the freezer compartment below freezing value before cooling the standby water supply, heating means operatively mounted on said standby water supply and energized for deliberate warming of the water in said standby water supply above said predetermined temperature and means operatively connecting said heating means to the water cooling control means for energization of the heating means in delayed response to reduction of the standby water supply below said predetermined temperature through heat exchange with the refrigerant circuit.

8. In combination with a refrigerator having a thermal circuit in heat exchange relation to a freezing compartment and a cold water container, compressor means operatively connected to the thermal circuit for operation thereof to sequentially lower the temperatures in the freezing compartment and the cold water container, heating means operatively mounted on the cold water container for elevating the temperature of the water therein, means responsive to the cooling demand of the freezing compartment for rendering the heating means operative to artificially elevate the temperature of the water in said cold water container, and temperature control means operatively connected to the compressor means for operating the thermal circuit solely in response to the cooling demand of the cold water container, whereby freezing of the water in the cold water container is prevented by said artificial warming of the water therein to create the cooling demand of the cold water container in delayed response to the cooling demand of the freezing compartment.

9. Refrigerating apparatus including a separate food and drink storage compartments and a water freezer unit within said food compartment, a water cooler in said drink storage compartment comprising a tank and a refrigerating coil surrounding the tank, a heater mounted on the tank separate from the refrigerating coil to artificially elevate the temperature of the water in the water cooler, at refrigerating coil in the Water freezing unit connected in series With the water cooler coil for favored cooling of the water in thewa-ter freezer unit, and a thermal responsive control device on the water cooler connected to the heater and adjusted to operate on a'temperature at the water cooler to which the water is elevated before ice in the water freezer unit rises to a temperature approaching its melting point.

References Cited by the Examiner UNITED STATES PATENTS 2,133,955 10/1938 Buchanan 62202 2,605,621 8/1952 Kellershan 62379 3,035,418 5/1962 Wright 62-180 3,105,364 10/1963 OConnell 62202 ROBERT A. OLEARY, Primary Examiner. MEYER PERLIN, Examiner. 

1. IN COMBINATION WITH A COMBINED WATER COLLER AND REFRIGERATOR HAVING A SINGLE REFRIGERANT CIRCUIT IN HEAT EXCHANGE RELATION WITH A FREEZER COMPARTMENT AND A STANDBY WATER SUPPLY, A CONTROL SYSTEM COMPRISING, WATER COOLING CONTROL MEANS RESPONSIVE EXCLUSIVELY TO INCREASE IN TEMPERATURE OF WATER IN SAID STANDBY WATER SUPPLY ABOVE A PREDETERMINED TEMPERATURE FOR RENDERING SAID REFRIGERANT CIRCUIT OPERATIVE TO SUBSTANTIALLY LOWER THE TEMPERATURE IN THE FREEZER COMPARTMENT TO A LOWER LIMIT BEFORE COOLING THE STANDBY WATER SUPPLY, HEATING MEANS OPERATIVELY MOUNTED ON SAID STANDBY WATER SUPPLY FOR DELIBERATE WARMING OF THE WATER THEREIN ABOVE SAID PREDETERMINED TEMPERATURE, AND FREEZE DEMAND MEANS OPERATIVELY CONNECTED TO SAID HEATING MEANS FOR ENERGIZATION THEREOF TO WARM THE WATER ONLY IN RESPONSE TO A RISE IN TEMPERATURE OF THE FREEZER COMPARTMENT ABOVE SAID LOWER LIMIT PRIOR TO SAID INCREASE IN TEMPERATURE OF THE WATER IN THE STANDBY WATER SUPPLY ABOVE THE PREDETERMINED TEMPERATURE. 